Treatment of basilar artery bifurcation aneurysms by using Guglielmi detachable coils: a 6-year experience

Overview of perianeurysmal edema following the endovascular management of cerebral aneurysms: A pooled analysis of 48 cases

BACKGROUND

Perianeurysmal edema occurring after endovascular treatment for cerebral aneurysms is uncommon compared to surgical clipping. The clinical aspects and the exact explanation are poorly understood.

METHODS

We searched PubMed, Google Scholar, and Web of Science. We used the following keywords: "endovascular management of cerebral aneurysms," "perianeurysmal cerebral edema," "perianeurysmal cerebral edema after endovascular treatment endovascular treatment," "intracranial aneurysms with perianeurysmal edema," and "vessel wall enhancement after endovascular therapy." For each case, demographic, clinicopathological, therapeutic, and follow-up data were gathered and analyzed.

RESULTS

Perianeurysmal edema after endovascular treatment has a clear female predilection, with a male: female ratio of 12:29 (25%; 60.41%). The average time from EVT to the onset of edema ranged from 1 day to about 8 years. The aneurysm dimension ranged from 6.8 to 25 mm as the largest size reported. Most patients were asymptomatic (18 [37.5 %]), and headache was the presenting symptom in 10 patients (20.8%). Aneurysmal wall enhancement was reported in 16 (33.3 %) patients with perianeurysmal edema. About 12 patients (25%) developed post-EVT hydrocephalus. The most common coil used was the platinum type (31 [64.58%]). Most of the patients were treated expectantly with follow-up (17 [35.41 %]), while steroids were used only in 14 (29.16%) patients. Most of the patients have their edema resolved (29 [60.41%]) or stable (9 [37.5%]).

CONCLUSION

There is growing evidence supporting the incidence of post-embolization inflammatory reactions involving the vessel wall and the surrounding parenchyma; however, the exact clinical perspectives and the predisposing factors are not fully uncovered. This analysis highlights the possible presentations and short-term outcome of patients presenting with perianeurysmal edema after endovascular management of cerebral aneurysms.

Microsurgery for basilar apex aneurysms: a case series

Although endovascular management has been increasingly adopted for basilar apex aneurysms (BAAs), microsurgery still represents an amenable treatment option. In this case series, six female patients (median age: 46 years) with six saccular high-riding BAAs (50% ruptured) were included. The median neck size was 5.3 mm (range: 2.9-7.9), and the median length from base to dome was 7.25 mm (range: 5.2-11.4). Preoperative complications included hydrocephalus (22%) and rebleeding (22%). All patients underwent clipping with a pterional craniotomy with extension into the temporal bone base. Intraoperative aneurysm rupture occurred in one patient (17%). Postoperative complications occurred in two patients (34%), of which one died because of extensive cerebral vasospasm and hospital-acquired pneumonia. At the 6-month follow-up, all remaining patients had modified Rankin scale scores ≤ 2. Microsurgery remains a viable option for BAAs in limited-resource settings. Technical success depends on delicate tissue work, in-depth anatomical knowledge, and maneuverability in narrow corridors.

Risk factors for perianeurysmal vasogenic oedema (pavo) following embolization therapy: literature review

Perianeurysmal vasogenic oedema (PAVO) is a rare complication associated post-embolisation of intracranial aneurysms. The prevalence, risk factors predisposing to susceptibility, and pathologic mechanisms underlying this process are not clearly understood. Since this complication may be associated with poor clinical outcomes, the authors designed this study to describe possible risk factors, underlying mechanisms, and management of PAVO through published case reports. Developing a priori protocol according to PRISMA guidelines, we searched MEDLINE/PubMed, Embase and Web of Science to identify case studies and reports of adult patients with intracranial aneurysms who developed perianeurysmal oedema following coil embolization therapy. Data extracted from these studies included patient demographics, aneurysm characteristics, coil type, PAVO characteristics, treatment, and outcomes. Quality was assessed using a standardized tool. 21 eligible studies of acceptable quality were identified, comprising 40 unique cases from 9 countries. The mean patient age was 56.4 years and 25 (62.5%) were female. Aneurysm size ranged from 6 to 30 mm, with a mean size of 15.2 mm; only 6 (15%) of cases were giant intracranial aneurysm (≥ 25 mm). The more frequent locations of intracranial aneurysms associated with PAVO were the ICA (50%) and posterior circulation (32.5%), with 7.5% and 10% of cases occurring in MCA and anterior circulation, respectively. 16 cases (40%) were treated with bare platinum coils, and 14 (35%) with a combination of BPCs and bioactive coils; in 10 cases (25%), the coil type was not mentioned. PAVO presented between 0 days and 8 years of coil embolization, with 23 (57.5% cases) presenting symptomatically in relation to brain region affected. Management strategies for PAVO included conservative, steroids, re-embolization, clipping, stenting, parent artery occlusion either as monotherapy or as combination therapy. Of reported studies, 26 treated cases (65%) resolved, with 8 (20%) remaining stable, and 4 (10%) deteriorating. PAVO can be associated with small or large intracranial aneurysms, bare and bioactive platinum coils, and all regions of the intracranial circulation. The understanding of the risk factors of this complication lies in the underlying mechanisms, which will ultimately guide appropriate patient follow-up and subsequent optimal management.

Impact of size ratio on thromboembolic events based on diffusion-weighted imaging after coil embolization for unruptured basilar apex aneurysm

PURPOSE

Coil embolization is one of the main endovascular treatment for basilar apex aneurysms (BAAs), and thromboembolic events are important complications of coil embolization. Even in small aneurysms, there is a risk of rupture, and aggressive treatment should be considered for unruptured BAAs. Using diffusion-weighted imaging (DWI), the study aimed to investigate thromboembolic events after coil embolization for unruptured BAAs by focusing on the absolute aneurysm size and relative aneurysm size (size ratio [SR]).

METHODS

To evaluate the predictors of thromboembolic events, patients were divided into those with and without hyperintensity on DWI after coil embolization. Patient and radiographic characteristics were compared between the two groups. SR was defined as the maximum aneurysm diameter divided by the average parent artery diameter.

RESULTS

Fifty-six unruptured BAAs in 56 patients were investigated. The mean aneurysm size and SR were 7.61 ± 2.18 mm and 2.74 ± 1.45, respectively. Postprocedural hyperintensity on DWI was detected in 17 patients (30.4%). SR was significantly larger in the group with hyperintensity on DWI (3.75 ± 1.97 vs. 2.3 ± 0.82, P < 0.01) in the univariate analysis. Multivariate analysis revealed that SR> 3.0 was a significant predictor of thromboembolic events after coil embolization for unruptured BAAs (odds ratio: 12.15; 95% confidence interval: 2.95-49.98; P < 0.01).

CONCLUSIONS

This study showed that SR is a predictor of thromboembolic events after coil embolization for unruptured BAAs. Therefore, if even in small BAAs, if the BAAs dome height is large compared to the diameter of the posterior cerebral artery (e.g., there is a large SR), preoperative evaluation of the use of antiplatelet therapy is important, particularly to prevent thromboembolic events.

Basilar apex aneurysm systematic review: Microsurgical versus endovascular treatment

BACKGROUND

Both microsurgical and endovascular techniques continued to be treatment options for basilar apex aneurysms (BAA). We conducted a systematic review to compare both treatment options in terms of both clinical and radiological outcomes.

METHODS

The PRISMA method was used to identify related articles. Data collected from each article and the two treatment approaches were compared in terms of favorable clinical outcome and complete/near complete occlusion rate. Subgroup analysis was done based on the size and the rupture status of BAA.

RESULTS

Fifty-nine (59) and 32 articles reported a measurable clinical and radiological outcome respectively. The weighted average favorable clinical outcome was significantly higher in the endovascular group (86.4% vs 79.6%, P<0.0001), while the weighted average complete/near complete occlusion rate was significantly higher in the surgical group (92.6% vs 83.8%, P<0.0001). In the subgroup analysis, the favorable clinical outcome remained significantly higher in the endovascular group for the ruptured, unruptured and giant/large BAA (P<0.001), but not in the small BAA subgroup (P=0.26). The occlusion rate remained significantly higher in the surgical group for all subgroups (P<0.001).

CONCLUSION

Treatment of BAA remains in a trade-off between favorable clinical outcome and complete or near-complete occlusion depending on the treatment modality selected. Careful selection of cases and judicial discussion between open surgical and endovascular team is warranted for treatment optimization.

Combined standard bypass and parent artery occlusion for management of giant and complex internal carotid artery aneurysms

BACKGROUND

Complex aneurysms do not have a standard protocol for treatment. In this study, we investigate the safety and efficacy of microsurgical revascularization combined with parent artery occlusion (PAO) in giant and complex internal carotid artery (ICA) aneurysms.

METHODS

Between 1998 and 2017, 41 patients with 47 giant and complex ICA aneurysms were treated by an a priori planned combined treatment strategy. Clinical and radiological outcomes were stratified according to mRS and Raymond classification. Bypass patency was assessed. Median follow-up time was 3.9 years.

RESULTS

After successful STA-MCA bypass, staged endovascular (n=37) or surgical (n=1) PAO was executed in 38 patients following a negative balloon occlusion test. Intolerance to PAO led to stent/coil treatments in two patients. Perioperative bypass patency was confirmed in 100% of completed STA-MCA bypass procedures. Long-term overall bypass patency rate was 99%. Raymond 1 occlusion and good outcome were achieved in 95% and 97% (mRS 0-2) of cases, respectively. No procedure-related mortality was encountered. Eighty-four percent of patients with preoperative cranial nerve compression syndromes improved during follow-up.

CONCLUSIONS

The combined approach of STA-MCA bypass surgery followed by parent artery occlusion achieves high aneurysm occlusion and low morbidity rates in the management of giant and complex ICA aneurysms. This combined indirect approach represents a viable alternative to flow diversion in patients with cranial nerve compression syndromes or matricidal aneurysms, and may serve as a backup strategy in cases of peri-interventional complications or lack of suitable endovascular access.

Endovascular embolization versus surgical clipping in a single surgeon series of basilar artery aneurysms: a complementary approach in the endovascular era

Background

Currently, most basilar artery aneurysms (BAAs) are treated endovascularly. Surgery remains an appropriate therapy for a subset of all intracranial aneurysms. Whether open microsurgery would be required or utilized, and to what extent, for BAAs treated by a surgeon who performs both endovascular and open procedures has not been reported.

Methods

Retrospective analysis of prospectively maintained, single-surgeon series of BAAs treated with endovascular or open surgery from the first 5 years of practice.

Results

Forty-two procedures were performed in 34 patients to treat BAAs—including aneurysms arising from basilar artery apex, trunk, and perforators. Unruptured BAAs accounted for 35/42 cases (83.3%), and the mean aneurysm diameter was 8.4 ± 5.4 mm. Endovascular coiling—including stent-assisted coiling—accounted for 26/42 (61.9%) treatments and led to complete obliteration in 76.9% of cases. Four patients in the endovascular cohort required re-treatment. Surgical clip reconstruction accounted for 16/42 (38.1%) treatments and led to complete obliteration in 88.5% of cases. Good neurologic outcome (mRS ≤ 2) was achieved in 88.5% and 75.0% of patients in endovascular and open surgical cohorts, respectively (p = 0.40). Univariate logistic regression analysis demonstrated that advanced age (OR 1.11[95% CI 1.01–1.23]) or peri-procedural adverse event (OR 85.0 [95% CI 6.5–118.9]), but not treatment modality (OR 0.39[95% CI 0.08–2.04]), was the predictor of poor neurologic outcome.

Conclusions

Complementary implementation of both endovascular and open surgery facilitates individualized treatment planning of BAAs. By leveraging strengths of both techniques, equivalent clinical outcomes and technical proficiency may be achieved with both modalities.

Neurosurgical management of aneurysms of the vertebrobasilar system: increasing indications for endovascular therapy with a continued role for open microneurosurgery

Aneurysms of the vertebrobasilar system remain among the most challenging subsets of aneurysms to treat with an open surgical approach. Since Charles Drake's pioneering work in the 1960s, several advances in microsurgical techniques have improved outcomes and feasibility in the open surgical management of these aneurysms. In parallel, the field of endovascular neurosurgery has provided several safe and effective treatment options. Multiple trials have suggested that endovascular therapy for aneurysms of the vertebrobasilar system is superior to open surgical management in most cases. In some instances, however, open surgical management likely represents a more effective and durable option relative to endovascular therapy. Therefore, continued training of future cerebrovascular specialists in open surgery of vertebrobasilar aneurysms remains crucial. With widespread utilization of endovascular techniques, however, proper exposure of trainees to such aneurysms is growing increasingly difficult. In this review, we discuss the recent advances in the endovascular management of vertebrobasilar aneurysms while also emphasizing the continued importance of open microneurosurgery in such cases.

Endovascular Temporary Balloon Occlusion for Microsurgical Clipping of Posterior Circulation Aneurysms

Based on the relationship between the posterior clinoid process and the basilar artery (BA) apex it may be difficult to obtain proximal control of the BA using temporary clips. Endovascular BA temporary balloon occlusion (TBO) can reduce aneurysm sac pressure, facilitate dissection/clipping, and finally lower the risk of intraoperative rupture. We present our experience with TBO during aneurysm clipping of posterior circulation aneurysms within the setting of a hybrid operating room (hOR). We report one case each of a basilar tip, posterior cerebral artery, and superior cerebellar artery aneurysm that underwent surgical occlusion under TBO within an hOR. Surgical exposure of the BA was achieved with a pterional approach and selective anterior and posterior clinoidectomy. Intraoperative digital subtraction angiography (iDSA) was performed prior, during, and after aneurysm occlusion. Two patients presented with subarachnoid hemorrhage and one patient presented with an unruptured aneurysm. The intraluminal balloon was inserted through the femoral artery and inflated in the BA after craniotomy to allow further dissection of the parent vessel and branches needed for the preparation of the aneurysm neck. No complications during balloon inflation and aneurysm dissection occurred. Intraoperative aneurysm rupture prior to clipping did not occur. The duration of TBO varied between 9 and 11 min. Small neck aneurysm remnants were present in two cases (BA and PCA). Two patients recovered well with a GOS 5 after surgery and one patient died due to complications unrelated to surgery. Intraoperative TBO within the hOR is a feasible and safe procedure with no additional morbidity when using a standardized protocol and setting. No relevant side effects or intraoperative complications were present in this series. In addition, iDSA in an hOR facilitates the evaluation of the surgical result and 3D reconstructions provide documentation of potential aneurysm remnants for future follow-up.

Zygomatic Anterior Temporal Approach for High-position Upper Basilar Aneurysm

Skull base techniques have often required high-position upper basilar aneurysm surgery based on a surgical corridor. Examples are the orbitozygomatic osteotomy for the trans-sylvian approach and zygomatic osteotomy for the subtemporal approach. However, clarity remains to be archived for the additional technique of the anterior temporal approach, including the middle surgical corridor of the trans-sylvian approach and subtemporal approach. In the present study, we describe the methodology and the problems associated with the zygomatic anterior temporal approach for high-position upper basilar artery aneurysms. Between 2007 and 2018, a total of 14 consecutive patients were received the same procedures of the zygomatic anterior temporal approach for high-position upper basilar aneurysms. Additionally, four patients underwent additional techniques to acquire further wide retro-carotid space. Complete ligation of all aneurysms was archived through the wide retro-carotid space in the absence of major surgical complications. Using the zygomatic anterior temporal approach, it is possible to both acquire a wide retro-carotid space and perform safety clip ligation of high-position upper basilar aneurysms without orbiotomy. However, additional orbiotomy should be taken into consideration by the surgeons if the orbital rim or internal carotid artery interferes with the surgical instruments or procedures.

Management of choroid plexus tumors-an institutional experience

Background

Choroid plexus tumors are rare entities. Resection is the mainstay of treatment in grade I and grade II tumors and adjuvant treatment is usually reserved for the less frequent choroid plexus carcinoma (CPC). Outcome is not only related to their histological grade but also dependent on their size, location, and presence of often multifactorial disturbances of cerebrospinal fluid (CSF) circulation.

Methods

Retrospective analysis of 36 consecutive patients operated on a choroid plexus tumor at our institution in a mixed pediatric and adult population between 1991 and 2016.

Results

Twenty-one CPP, 11 atypical choroid plexus papillomas (aCPP), and four CPC were encountered in 17 children and 19 adults. Regardless of histological grading, gross-total resection (GTR) could be achieved in 91.7% of patients. Tumor recurrence (25.0%) was significantly associated with histological grading (p = 0.004), subtotal resection (p = 0.002), and intraoperatively evident zones of tumor infiltration (p = 0.001). Adjuvant therapy was performed in 19.4% of patients, mainly diagnosed with CPC. The 5-year overall survival rate was 95.2% for CPP and 100.0% for both aCPP and CPC. Survival was related to the extent of resection (p = 0.001), tumor progression (p = 0.04), and the presence of leptomeningeal metastases (p = 0.002). Even after resection, either ventricular or subdural shunting was required in 25.0% of patients.

Conclusions

We could confirm that GTR is crucial for treatment of choroid plexus tumors. Parenchymal tumor infiltration as detected intraoperatively was associated with the extent of resection and not limited to CPC. CSF disturbances mandating treatment may persist after resection.

Wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques: a multicentre, core lab adjudicated study evaluating safety and durability of occlusion (BRANCH)

Background and purpose

BRANCH (wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques) is a multicentre, retrospective study comparing core lab evaluation of angiographic outcomes with self-reported outcomes.

Materials and methods

Consecutive patients were enrolled from 10 US centres, aged between 18 and 85 with unruptured wide-neck middle cerebral artery (MCA) or basilar apex aneurysms treated endovascularly. Patient demographics, aneurysm morphology, procedural information, mortality and morbidity data and core lab and self-reported modified Raymond Roy (RR) outcomes were obtained.

Results

115 patients met inclusion criteria. Intervention-related mortality and significant morbidity rates were 1.7% (2/115) and 5.8% (6/103) respectively. Core lab adjudicated RR1 and 2 occlusion rates at follow-up were 30.6% and 32.4% respectively. The retreatment rate within the follow-up window was 10/115 (8.7%) and in stent stenosis at follow-up was 5/63 (7.9%). Self-reporting shows a statistically significant direction to angiographic RR one outcomes at follow-up compared with core lab evaluation, with OR 1.75 (95% CI 1.08 to 2.83).

Conclusion

Endovascular treatment of wide-neck MCA and basilar apex aneurysms resulted in a core lab adjudicated RR1 occlusion rate of 30.6%. Self-reported results at follow-up favour better angiographic outcomes, with OR 1.75 (95% CI 1.08 to 2.83). These data demonstrate the need for novel endovascular devices specifically designed to treat complex intracranial aneurysms, as well as the importance of core lab adjudication in assessing outcomes in such a trial.

Should we still consider clips for basilar apex aneurysms? A critical appraisal of the literature

Background:

Basilar apex aneurysms constitute 5–8% of all intracranial aneurysms, and their treatment remains challenging for both microsurgical and endovascular approaches. The perceived drawback of the microsurgical approach is its invasiveness leading to increased surgical morbidity. However, many high-volume centers have shown excellent clinical results with better occlusion rates compared to endovascular treatment. With endovascular therapy taking a larger role in the management of cerebral aneurysms, the future role of microsurgery for basilar apex aneurysm treatment is unclear.

Methods:

We performed a literature search to review the microsurgical and endovascular outcomes for basilar apex aneurysms.

Results:

Many studies have examined the efficacy of microsurgical and endovascular treatment for intracranial aneurysms, including large randomized trials such as ISAT and BRAT, prospective observational series such as ISUIA, and many single-center retrospective reviews. The recruitment number for posterior circulation aneurysms, specifically for basilar apex aneurysms, was limited in most prospective trials, thus failing to offer clear guidance on basilar apex aneurysm treatment. Recent single-center series report good clinical outcomes between 57–92% for surgical series and 73–96% in endovascular series. The durability of aneurysm occlusion remains superior in surgical cases. The techniques and devices in endovascular treatment have improved treatment aneurysm occlusion rates but more follow-up is needed to confirm long-term durability.

Conclusions:

Both microsurgical and endovascular approaches should be complementing each other to treat basilar apex aneurysms. Although endovascular therapy has taken a larger role in the treatment of basilar apex aneurysms, many indications still exist for the use of microsurgery. Advancements in microsurgical techniques and good case selection will allow for acceptably low morbidity after surgical treatment while maintaining its superior durability.

Endovascular Treatment of Intracranial Aneurysms: Long-Term Follow-up

Endovascular treatment of intracranial aneurysms is increasingly used and has evolved as an alternative to surgical clipping. However, its long-term efficacy has yet to be established. This retrospective hospital based (tertiary teaching hospital) study aimed to identify factors that might be important in predicting initial efficacy of this treatment and a long-term follow-up to study the clinical and angiographic results of treated aneurysms. A total of 80 aneurysms in 78 patients were treated and analyzed, and the percentage of occlusion calculated. Overall, 51/80 (64 %) cases were treated with selective endovascular coil occlusion and 29/80 (36 %) by parent artery occlusion. The shape of the aneurysm rest was noted on the immediate post treatment and follow-up angiograms. Immediate and follow-up clinical status was also noted using the Glasgow outcome scale. The clinical and radiological changes on follow-up were assessed and possible factors involved were analyzed. Of the 50 patients of intracranial aneurysms that underwent selective aneurysm coiling, good immediate outcome (Glasgow outcome scale 1 and 2) was seen in 36/50 (72 %) cases. Narrow necked aneurysms showed a good immediate result (90–100 % packing) in all cases 28/28 (100 %). Amongst the wide necked aneurysms, good packing (90–100 %) was achieved in 17/23 (73 %) cases. Amongst the cases treated with parent artery occlusion, complete occlusion was noted in 20/29 (69 %) cases. No subarachnoid hemorrhage was seen in any of the followed up cases of coiled aneurysms. A statistically significant relationship was noted between aneurysm neck size and immediate angiographic outcome. Long-term angiographic recurrences were found more often in large aneurysms. Endovascular treatment of intracranial aneurysms is a safe and effective treatment modality that offers protection from recurrent subarachnoid hemorrhage.

Rebleeding of Ruptured Intracranial Aneurysms in the Immediate Postoperative Period after Coil Embolization

Objective

Early rebleeding after coil embolization of ruptured intracranial aneurysms is rare, however serious and fatal results of rebleeding have been reported. We studied the incidence and angiographic and clinical characteristics of rebleeding of ruptured aneurysms occurring in the immediate postoperative period after coil embolization.

Materials and Methods

We analyzed patients who had aneurysmal subarachnoid hemorrhage and underwent coil embolization. Patients with dissecting aneurysms, blood blister-like aneurysms, fusiform aneurysms, and pseudoaneurysms were excluded. This study included 330 consecutive patients. The clinical and radiological data of 7 of these patients with acute rebleeding after coil embolization were reviewed.

Results

The incidence of rebleeding of ruptured aneurysms after coil embolization was 2.1% (7/330), and all cases of rebleeding occurred in the immediate postoperative period within 3 days after coiling. The radiological characteristics were as follows: anterior communicating artery (ACoA) aneurysm (71.4%, 5/7); presence of intracerebral hemorrhage (ICH, 71.4%, 5/7); dome-to-neck ratio < 2 (42.9%, 3/7); presence of bleb (42.9%, 3/7); and subtotal occlusion of aneurysm after coiling (14.3%, 1/7). A thrombolytic agent was administered in 1 patient and continued anticoagulation was performed in 2 patients. Rebleeding patients showed a very poor outcome (Glasgow Outcome Scale 1, 85.7%, 6/7).

Conclusion

The prognosis of early rebleeding was very poor. Location of aneurysms on ACoA, the unilateral hypoplasia of A1 segment, presence of ICH and bleb, and adverse events during the procedure were probably associated with early rebleeding of ruptured intracranial aneurysms in the immediate postoperative period after coil embolization.

Factors Predicting the Oculomotor Nerve Palsy following Surgical Clipping of Distal Vertebrobasilar Aneurysms: A Single-Institution Experience

Background The aim of our study was to identify various clinical and radiologic factors that correlate with the oculomotor nerve palsy following clipping of distal vertebrobasilar aneurysms. Methods A total of 48 patients with 51 aneurysms were included in this retrospective study . Patient's age, gender, size, location, and projection of the aneurysm, preoperative Hunt and Hess (H&H) grade, presence of subarachnoid hemorrhage (SAH), temporary clipping, preoperative third nerve palsy, and Glasgow Outcome Scale were included in the model for analysis. Results A total of 15 patients (31.25%) developed oculomotor nerve palsy following clipping of basilar apex aneurysms. 38 patients (79.2%) presented with SAH and 35 patients (72.9%) had poor H&H grades at presentation. The size of the aneurysm (p = 0.03), preoperative H&H grade (p = 0.04), preoperative oculomotor nerve dysfunction (p = 0.007), and projection of an aneurysm (p = 0.004) had shown a significant correlation with the oculomotor nerve palsy. The size of the aneurysm (p = 0.030, odds ratio: 0.381; 95% confidence interval, 0.175-0.827] was an independent predictor of postoperative nerve dysfunction. Conclusion The size of the aneurysm, clinical grade at presentation, and projection of the aneurysm correlated with the oculomotor nerve dysfunction following clipping. These clinical and radiologic parameters can be used to predict the oculomotor nerve outcome.

Bypass and flow reduction for complex basilar and vertebrobasilar junction aneurysms

BACKGROUND

Giant aneurysms of the vertebral and basilar arteries are formidable lesions to treat.

OBJECTIVE

To evaluate the long-term outcomes of patients with vertebrobasilar aneurysms treated with extracranial-intracranial bypass and flow reduction.

METHODS

We retrospectively reviewed a prospective database of aneurysms cases treated between December 1993 and August 2011.

RESULTS

Eleven patients (8 male, 3 female) with 12 aneurysms were treated. There were 3 basilar apex aneurysms, 2 aneurysms of the basilar trunk, and 7 vertebrobasilar junction aneurysms. There were 5 saccular and 7 fusiform aneurysms. All patients underwent extracranial-intracranial bypass and vessel occlusion. Flow was reversed or reduced by complete (n = 6) or partial occlusion of the basilar artery (n = 3) or by occlusion of the vertebral arteries distal to the posterior inferior cerebellar artery (n = 3). Postoperatively (mean follow-up, 71.6 months; range, 4-228; median, 49 months), the bypass patency rate was 92.3% (12/13). The perioperative mortality rate for the initial treatment was 18.2% (2/11). In 4 cases, the aneurysms continued to grow and required further treatment; after re-treatment, 3 of these patients died. Of the initial 11 patients, 6 were treated successfully and 5 died. The mean preoperative modified Rankin Scale score was 2.1 (range, 1-3; median, 2). At last follow-up for all patients, the mean modified Rankin Scale score was 3.45 (range, 1-6; median, 3) and 2.5 (range, 1-4; median, 2.5) for the 6 long-term survivors.

CONCLUSION

Vertebrobasilar aneurysms are challenging lesions with limited microsurgical or endovascular options. Despite aggressive surgical treatment, the long-term outcome remains poor for most patients.

Safety and efficacy of endovascular treatment of basilar tip aneurysms by coiling with and without stent assistance: a review of 235 cases

BACKGROUND

Endovascular therapy is now the preferred treatment option for basilar tip aneurysms (BTAs).

OBJECTIVE

To compare the safety and efficacy of common endovascular techniques in the treatment of BTAs.

METHODS

A retrospective review was conducted of 235 patients with BTAs treated with endovascular means in our institution between 2004 and 2011. Categorization was based on the presence and type of stent assistance (none, single, and Y stenting). The rates of perioperative complications, recanalization, rehemorrhage, and retreatment were analyzed.

RESULTS

A total of 147 patients were treated with coil embolization and 88 patients with stent-assisted coiling (72 single stents, 16 Y stents). Thromboembolic complications occurred in 6.8% of patients in both groups. There was no associated mortality. Angiographic follow-up (mean, 23.5 months) was available in 172 patients (77.1%). Stented patients had significantly lower recanalization (17.2% vs 38.9%; P=.003) and retreatment (7.8% vs 27.8%; P=.002) rates compared with nonstented patients. Four rehemorrhages (2.7%) occurred in the coiled group, whereas none were noted in the stented group (P=.3). In paired comparisons, lower recanalization (8.3% vs 19.2%; P=.21) and retreatment (0% vs 9.6%; P=.19) rates were seen in the Y-stent group compared with the single-stent group. Thromboembolic complications occurred in 6.9% and 6.2% of patients in the single-stent and Y-stent groups, respectively (P=.91). In multivariate analysis, larger aneurysms, nonstented aneurysms, incomplete initial occlusion, and subarachnoid hemorrhage were predictors of aneurysm recanalization.

CONCLUSION

Stent-assisted coiling has significantly lower recurrence, retreatment, and rehemorrhage rates than coiling alone for the treatment of BTAs. Y stenting has the highest efficacy with low complication rates.

Surgical treatment for vertebral artery-posterior inferior cerebellar artery aneurysms: special reference to the importance of the cerebellomedullary fissure dissection

OBJECT

The cerebellomedullary fissure (CMF) is a space between the cerebellum and the medulla oblongata, which often adhere to each other. The purpose of the present study was to demonstrate the importance of the unilateral CMF dissection for clipping vertebral artery (VA)-posterior inferior cerebellar artery (PICA) aneurysms.

METHODS

Five adult cadaveric specimens were studied after colored silicone was infused into the arteries and veins. The microsurgical anatomy of the CMF and the trans-CMF approach for VA-PICA aneurysm surgery were examined in stepwise dissections. In addition, 6 patients underwent surgery for VA-PICA saccular aneurysms (2 ruptured and 4 unruptured aneurysms) via posterolateral approaches, with wide opening of the unilateral CMF to obtain good visualization and a wide working space in the lateral part of the cerebellomedullary cistern. Clinical data including neurological and radiological findings and patient outcomes were analyzed in all 6 cases.

RESULTS

In all cases, the aneurysm was successfully clipped and no permanent neurological deficits remained. The wide opening of the unilateral CMF on the lesion side made it possible to retract the inferolateral part of the cerebellum easily, provided a wide operative field in the cerebellomedullary cistern, and enabled successful clip placement without difficulty.

CONCLUSIONS

For safe and effective VA-PICA aneurysm surgery, it is very important to dissect the CMF on the lesion side as well as to remove the lateral part of the foramen magnum. Direct clip placement is very safe and useful in cases involving VA-PICA aneurysms.

A novel tissue engineering approach using an endothelial progenitor cell–seeded biopolymer to treat intracranial saccular aneurysms

Object

Recurrence after endovascular coiling of intracranial aneurysms is reported in up to 42% of cases and is attributed to the lack of endothelialization across the neck. In this study the authors used a novel tissue engineering approach to promote endothelialization by seeding endothelial progenitor cells (EPCs) within a fibrin polymer injected endovascularly into the aneurysm.

Methods

Experimental aneurysms were created in New Zealand White rabbits and were left untreated, surgically clipped, or embolized with platinum coils, fibrin biopolymer alone, or fibrin combined with autologous cultured EPCs.

Results

In aneurysms treated with EPCs, a confluent monolayer of endothelial cells with underlying neointima was demonstrated across the neck at 16 weeks posttreatment, which was not observed with aneurysms treated using the other methods.

Conclusions

This novel technique may address reasons for the limited durability of standard coil embolization and provides further avenues for the development of improved devices for the care of patients with aneurysms.

Complex basilar artery aneurysms treated using surgical basilar occlusion: a modern case series

Object

Complex aneurysms of the basilar artery (BA) apex can be successfully treated using surgical occlusion of the proximal BA. Since the introduction of the Guglielmi detachable coil in 1991, the focus on treating BA aneurysms has been on using endovascular techniques. Outcomes with endovascular techniques have been less than optimal for large and complex aneurysms. The authors therefore report on their current 22-year experience with surgical BA occlusion for complex BA aneurysms and long-term outcome.

Methods

Fifteen patients underwent surgical BA occlusion at Columbia University Medical Center for complex basilar apex aneurysms between 1987 and 2009. The clinical records of each patient were reviewed for details of presentation, hospital course, operative intervention, and outcome.

Results

Postoperatively, all patient encounters were recorded at discharge, at the 1-month and 1-year follow-up evaluations, and at long-term outcome. Twelve (80%) of 15 patients experienced no new postoperative neurological deficits. Three patients presenting with severe neurological impairment (modified Rankin Scale [mRS] score > 3) made excellent recoveries (mRS Scores 1–2) at long-term follow-up. One patient died, 1 suffered a stroke during the postoperative angiogram which resulted in hemiparesis, and 1 suffered internuclear ophthalmoplegia which resolved by the 1-month follow-up. Long-term follow-up occurred at an average of 3 ± 4.5 years, ranging from 2 months (for a recently treated patient) to 18 years. The average mRS score at long-term follow-up was 1 ± 1.5. No patient experienced postoperative hemorrhage, rebleeding, or delayed neurological deterioration.

Conclusions

Surgical occlusion of the BA is an effective treatment option offering a high rate of angiographic cure in a single procedure for patients with complex BA aneurysms. The ability to surgically perform point occlusion of the BA without impairment of brainstem perforators, while maintaining collateral blood flow to the posterior circulation branch vessels, may provide an advantage compared with endovascular treatments.

Early ceasing of intra-aneurysmal contrast opacification during coil embolization in ruptured aneurysms compared with unruptured aneurysms

BACKGROUND

The difference between coil-embolized ruptured and unruptured aneurysms with respect to intra-aneurysmal thrombus formation remains to be determined.

OBJECTIVE

We examined whether there was a difference between ruptured and unruptured coil-embolized aneurysms in the rate and timing of thrombus formation in the aneurysmal sac and discuss the effect of thrombus on the treatment outcome.

METHODS

We evaluated 209 aneurysms with an aneurysmal dome smaller than 10 mm and a neck size less than 4 mm. Of these, 91 (43.5%) were ruptured. We assessed intra-aneurysmal thrombus formation by the coil-packing ratio (CPR): the percentage of coil volume occupying the aneurysmal sac. The initial CPR was defined as the CPR at which contrast influx into the sac ceased and the final CPR as that at the end of the procedure. ΔCPR was calculated as the difference between initial and final CPRs. Embolized aneurysms were evaluated on follow-up angiograms.

RESULTS

The initial CPR was significantly lower in ruptured aneurysms (P < .01), and there was not a significant difference in the final CPR between ruptured and unruptured aneurysms (P = .05). ΔCPR was significantly higher in ruptured aneurysms (P < .01). The rate of aneurysmal recanalization was significantly higher in ruptured aneurysms (P < .05). The incidence of recanalization was high in ruptured aneurysms with low initial CPR and ΔCPR values.

CONCLUSION

In ruptured aneurysms, intra-aneurysmal thrombus formation tends to occur in the earlier stages of coil embolization. In some cases, thrombus formation may inhibit dense coil packing and result in recanalization.

Cardiac standstill for cerebral aneurysms in 103 patients: an update on the experience at the Barrow Neurological Institute. Clinical article

OBJECT

The aim of this study was to clarify the surgical indications, risks, and long-term clinical outcomes associated with the use of deep hypothermic circulatory arrest for the surgical treatment of intracranial aneurysms.

METHODS

The authors retrospectively reviewed 105 deep hypothermic circulatory arrest procedures performed in 103 patients (64 females and 39 males, with a mean age of 44.8 years) to treat 104 separate aneurysms. Patients' clinical histories, radiographs, and operative reports were evaluated. There were 97 posterior circulation aneurysms: at the basilar apex in 60 patients, midbasilar artery in 21, vertebrobasilar junction in 11, superior cerebellar artery in 4, and posterior cerebral artery in 1. Seven patients harbored anterior circulation aneurysms. Two additional patients harbored nonaneurysmal lesions.

RESULTS

Perioperatively, 14 patients (14%) died. Five patients (5%) were lost to late follow-up. At a mean long-term follow-up of 9.7 years, 65 patients (63%) had the same or a better status after surgical intervention, 10 (10%) were worse, and 9 (9%) had died. There were 19 cases (18%) of permanent or severe complications. The combined rate of permanent treatment-related morbidity and mortality was 32%. The mean late follow-up Glasgow Outcome Scale score was 4, and the annual hemorrhage rate after microsurgical clipping during cardiac standstill was 0.5%/year. Ninety-two percent of patients required no further treatment of their aneurysm at the long-term follow-up.

CONCLUSIONS

Cardiac standstill remains an important treatment option for a small subset of complex and giant posterior circulation aneurysms. Compared with the natural history of the disease, the risk associated with this procedure is acceptable.

Surgical management of intracranial aneurysms previously treated with endovascular therapy

Endovascular treatment with coils of cerebral aneurysm is being increasingly used for definitive treatment. An increasing number of patients are coming for surgical intervention either for recurrences, incomplete coil embolization or its complications. Our objective was to assess the surgical management in such patients. This was a retrospective analysis of the patients who were initially treated with endovascular embolization and later managed surgically with clipping either for unsuccessful coiling, recurrence of aneurysm or post-procedural complication, between 2003 and 2007. Anatomical results were excellent in all five patients, and all the aneurysms were totally excluded from the circulation. All patients had good recovery. None of the patients suffered any major intraoperative or postoperative complication. Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy is an emerging challenge, but with proper patient selection and careful planning, this subset of aneurysms can be managed with good results.

The small “surgical aneurysm” at the basilar apex

Object

Because the risks are reduced, larger basilar apex aneurysms are usually treated endovascularly instead of with surgery. However, small basilar apex aneurysms are more common and an unfavorable shape may prevent definitive endovascular treatment. The goal of this study was to reevaluate the outcome of traditional surgery for small unruptured basilar apex aneurysms as an alternative to the currently more accepted endovascular treatment.

Methods

The authors reviewed clinical data obtained in 21 patients who underwent surgery between 2000 and 2007 for unruptured basilar apex aneurysms < 7 mm.

Results

The median age of the 21 patients was 52 years (range 29–74 years). All patients experienced a good outcome. Two patients harbored a small residual aneurysm (> 95% occlusion). Eight patients (38%) suffered a temporary third nerve paresis, which resolved in all cases.

Conclusions

Surgical clip ligation remains an excellent treatment for small basilar apex aneurysms. The treatment is definitive and in experienced hands is associated with a low risk.

Acute serious rebleeding after angiographically successful coil embolization of ruptured cerebral aneurysms

PURPOSE

The present study investigated the incidence of acute rebleeding after successful coil embolization of a ruptured cerebral aneurysm, including clinical outcomes, and possible mechanisms of the events other than coil compaction and/or incomplete embolization.

MATERIALS AND METHODS

This study included 591 consecutive patients who presented with aneurysmal subarachnoid hemorrhage, were treated with coil embolization, and whose post-procedural angiography revealed successful embolization. Data were collected retrospectively from six patients who showed acute rebleeding despite that angiographically successful coil embolization was achieved. All clinical, radiological data and intraoperative videos were reviewed to identify causative factors which could have contributed to the occurrence of rebleeding.

RESULTS

Incidence of acute rebleeding after successful coil embolization of ruptured cerebral aneurysm was 1.0% (6/591). In all of these six patients, complete angiographic occlusion was achieved except in one case where a small residual neck was intentionally left to avoid compromise of the parent artery. Four of the six patients showed poor clinical courses, either died or recovered with severe disability. Whenever possible, we performed an immediate craniotomy for exploration and additional clipping. Based on intraoperative findings, we hypothesized that uneven distribution of the coil masses and spontaneous resolution of thrombus among the strands of coil (inter-coil-loop thrombolysis) could be possible mechanisms of rebleeding.

CONCLUSION

Acute rebleeding is extremely rare, but is possible as a complication of coil embolization of a ruptured cerebral aneurysm even when a case is angiographically successful. The higher degree of morbidity and mortality is a major concern. Therefore, further investigation to discover risk factors and causative mechanisms for such a complication is sorely needed.

Angiographic and clinical outcomes in 200 consecutive patients with cerebral aneurysm treated with hydrogel-coated coils

BACKGROUND AND PURPOSE

Denser coil packing in intracranial aneurysms is believed to result in lower recanalization rates. Hydrogel-coated expandable coils (HydroCoil) improve volumetric packing of aneurysms in animal models and clinical studies, but data from large clinical series are limited. The objective of this retrospective analysis was to analyze immediate and follow-up angiographic results as well as complications in a large consecutive series of patients treated with HydroCoils at a single institution.

MATERIALS AND METHODS

Retrospective analysis was performed of periprocedural complications, immediate and follow-up angiograms, and retreatments of the first 200 consecutive intracranial aneurysms treated at Emory University Hospital.

RESULTS

One hundred eighty-seven patients with 200 intracranial aneurysms were treated with HydroCoils during a 3-year period. Immediate angiograms showed complete aneurysmal obliteration in 58.4% of small aneurysms and 42.7% of large aneurysms. Periprocedural complications included early rebleeding and thromboembolic events resulting in permanent neurologic morbidity and mortality in 6% of cases. Follow-up angiography during an average of 16.3 months demonstrated recanalization in 17.7% of small aneurysms and 28.6% of large aneurysms, requiring retreatment in 6.3% and 19.0% of cases, respectively. During the same time period, there was delayed angiographic improvement in aneurysm obliteration in 26.6% of small aneurysms and 26.2% of large aneurysms.

CONCLUSIONS

First-generation HydroCoil treatment of intracranial aneurysms has a favorable rate of recanalization compared with most large series of pure platinum coils with similar complication rates.

Symptomatic perianeurysmal edema following bare platinum embolization of a small unruptured cerebral aneurysm

There is considerable interest in the development of symptomatic inflammatory reactions following coil embolization of cerebral aneurysms. Patients have experienced a range of adverse events, usually after treatment of moderately large aneurysms with modified "bioactive" coils. More recently, it has been recognized that adverse inflammatory reactions can be associated with the use of "nonbioactive" coils, and we present a case of symptomatic perianeurysmal edema after treatment of a small unruptured aneurysm with bare platinum coils.

Analysis of clinical and radiological outcomes in microsurgical and endovascular treatment of basilar apex aneurysms

OBJECTIVE

We aimed to analyze clinical and radiological outcomes retrospectively in patients with basilar apex aneurysms treated by coiling or clipping.

METHODS

Outcomes of basilar bifurcation aneurysms were assessed retrospectively in 77 consecutive patients (61 women, 16 men), ranging in age from 25 to 79 years (mean, 53.7 years) from 1999 to 2007.

RESULTS

Forty-nine patients out of 77 patients (63.6%) presented with subarachnoid hemorrhages of the 49 patients treated with coiling, 27 (55.1%) showed complete occlusion of the aneurysm sac. Of these, 13 patients (26.5%) developed coil compaction on angiographic or MRI follow-up, with recoiling required in 9 patients (18.4%). Procedural complications of coiling were acute infarction in nine patients and the bleeding of the aneurysms in six patients. The remaining 28 patients underwent microsurgery: twenty-six of these (92.9%) with microsurgery followed up with conventional angiography. Complete occlusion of the aneurysm sac was achieved in 19 patients (73.1%). Operation-related complications of microsurgery were thalamoperforating artery injuries in three patients, retraction venous injury in two, postoperative epidural hemorrhage (EDH) in one, and transient partial or complete occulomotor palsy in 14 patients. Glasgow Outcome Scores (GOS) were 4 or 5 in 21 of 28 (75%) patients treated with microsurgery at discharge, and at 6 month follow-up, 20 of 28 (70.9%) maintained the same GOS. In comparison, GOS of four or 5 was observed in 36 of 49 (73.5%) patients treated with coiling at discharge and at 6 month follow-up, 33 of 49 patients (67.3%) maintained the GOS from discharge.

CONCLUSION

Basilar top aneurysms were still challenging lesions based on our series. Endovascular or microsurgery endowed with its inborn risks and procedural complications for the treatment of basilar apex aneurysms individually. Microsurgery provided better outcome in some specific basilar apex aneurysms. For reaching the most favorable outcome, endovascular modality as well as microsurgery was inevitably considered for each specific basilar apex aneurysm.

Clinical and radiogical outcomes of endovascular detachable coil embolization in paraclinoid aneurysms : a 10-year experience

OBJECTIVE

Direct surgical clipping of paraclinoid aneurysms poses technical challenges to even very experienced neurosurgeons, making endovascular treatment an alternative treatment modality in many centers. We have therefore retrospectively evaluated the safety and efficacy of endovascular detachable coil embolization of paraclinoid aneurysms.

METHODS

From June 1997 to June 2007, 65 patients underwent endovascular detachable coiling for 67 paraclinoid aneurysms (of which 9 were ruptured and 58 were unruptured) in our institute. Their medical records, radiological images and readings, and operation records were reviewed retrospectively.

RESULTS

After the initial embolization procedure, complete occlusion was achieved in 29 (43.3%) of the aneurysms treated by endovascular detachable coiling. Six aneurysms required retreatment, with two each requiring one, two, or three additional endovascular procedures. Fifty-five (82.1%) aneurysms were measured by three-dimensional time of flight (TOF) magnetic resonance images (MRI) or transfemoral cerebral angiography (TFCA) at a mean follow-up of 29.7 months (range from 4 to 94 months), with 39 aneurysms (70.9%) showing complete occlusion. Thromboembolic events (3.8%) were the most frequent complication. Rupture did not occur during or after any of the procedures. According to the Glasgow Outcome Scale (GOS), 98.4% of the patients treated by coil embolization had a score of 4 or 5.

CONCLUSION

Our results indicate that endovascular detachable coiling is a safe and effective treatment modality in paraclinoid aneurysms.

Morphological study of aneurysms at the junction of the superior cerebellar artery

SUMMARY

Superior cerebellar artery (SCA) aneurysms sometimes involve the origin of the SCA making treatment difficult. We focused on the morphological characteristics of SCA aneurysms and adjacent vascular structures to apply clinical decision-making for the treatment strategy. Sixty-nine SCA aneurysms, including 34 ruptured and 35 unruptured ones, had been treated for over 12 years. Multiple aneurysms were associated in 30 patients. The pattern of the neck position of aneurysms was classified into three types: Type A: no SCA-involved type; Type B: half involved type with SCA originating from the aneurysmal neck; Type C: pure SCA aneurysm with all the neck mounting on SCA. Morphological and clinical analysis was done between ruptured and unruptured aneurysms and among the three types. There was no difference in patient profile between ruptured and unruptured aneurysms. The angle formed by the posterior cerebral artery and SCA on the aneurysm side was obtuse in 62 (90%) patients. From the morphological point of view the SCA-involved type (types B + C) was significantly more prevalent in ruptured aneurysms (77%). Bleb formation was particular in ruptured aneurysms. As for the treatment, the risk of SCA occlusion and incomplete and attempted operation was particularly high in cases with SCA-involved type. Although SCA aneurysms may grow due to the hemodynamic stress at the opened bifurcation between the PCA and SCA, the neck shifting to the origin of SCA, particularly in ruptured lesions,may suggest some other etiological mechanism. SCA-involved type aneurysms had a high treatment risk of SCA occlusion and tended to incomplete treatment to avoid such ischemic complications.

Plical resection in pre-temporal approach for basilar bifurcation aneurysms: preliminary surgical experience and cadaveric study

OBJECT

Although a pre-temporal approach (PA) can provide a wide space for preservation of thalamoperforating atrteries in direct surgery for basilar bifurcation aneurysms (BBAs), it cannot always secure adequate proximal control. The authors described the advantages of plical resection added to PA for BBAs.

METHODS

Between October 1998 and April 2000, eight consecutive patients with BBAs were treated in the neurosurgical department of Kurashiki Central Hospital. Among them, five patients received direct clipping using this method. There were four females and one male, ages ranging from 61 to 77 (mean 70.8 years). Mean aneurysmal size and distance between the in"terclinoidal line and the aneurysmal neck was 4.5 and 9.5 mm, respectively. The operative procedures consisted of the following components; 1) fronto-temporal craniotomy with translocation of orbito-zygomatico-malar bone for PA, 2) preservation of lateral branches of the superficial sylvian veins, 3) resection of plica dural folds to increase the operative field up to the oculomotor nerve (OMN).

RESULTS

Complete clipping was achieved without thalamic infarction or temporal contusion in all patients. Three of the five patients suffered from transient right OMN palsy which recovered within two months after surgery.

CONCLUSION

Plical resection in the pre-temporal approach might be beneficial in the surgical treatment of BBAs when proximal control seems difficult.

Endovascular embolization of intracranial aneurysms

Intracranial aneurysm (ICA) is a common condition but with a high mortality rate when rupture occurs. The treatment of ruptured or unruptured ICA, especially with an endovascular approach, has been evolving rapidly. The current generally accepted opinion suggests that endovascular embolization is an effective technique for preventing the recurrence of aneurysm rupture, but the rebleeding rate after endovascular embolization is found to be higher than that after surgical clipping. In addition, long-term follow-up data are required for the evaluation of the effectiveness of endovascular treatment in unruptured ICA. This review presents the current understanding of ICA, the selection of optimal treatment approaches, and in particular, the advances in endovascular embolization in the treatment of ICA, including embolic materials, therapeutic and assisting techniques, long-term effectiveness, and limitations.

Endovascular treatment of unruptured intracranial aneurysms with Guglielmi detachable coils: short- and long-term results of a single-centre series

BACKGROUND AND PURPOSE

Purpose of the present study is to evaluate the clinical outcome of endovascular treatment of unruptured intracranial aneurysms and to address the question of long-term stability and protection against future subarachnoid hemorrhage.

METHODS

Retrospective analysis of all patients treated in a 12-year period (173 patients: age 26 to 76 yr, mean 52.2+/-10.8/202 aneurysms: size 3 to 50 mm, mean 10.0+/-8.3).

RESULTS

The mortality was 0.5%; the overall morbidity was 3.5%. The most frequent complications were thromboembolic events (10.9%). Of these, 3.0% of patients suffered a stroke, leading to severe disability in 1 patient (0.5%). In 1 patient, the aneurysm ruptured during treatment, resulting in relevant neurological disability. Another patient suffered a fatal aneurysm rupture hours after treatment. The occlusion rate depended on aneurysm and neck size. Follow-up angiography revealed a decrease of the occlusion rate over time. This trend was obvious in all size categories and was most pronounced in giant aneurysms. In 3 patients (1.5%) with partially thrombosed giant aneurysms of the posterior circulation, embolization could not prevent later aneurysm rupture. There were no ruptures of any other aneurysms in the follow-up period (3.7+/-3.4 yr).

CONCLUSIONS

Endovascular treatment is a highly safe procedure with low intervention-related morbidity and mortality. Long-term data for nongiant aneurysms showed good protection against rupture in the observation period. In contrast, the risk of rupture for giant aneurysms of the posterior circulation was as high as expected in observational studies.

Basilar artery aneurysm treated with coil embolization via persistent primitive hypoglossal artery

A saccular aneurysm at the basilar artery bifurcation associated with a persistent primitive hypoglossal artery (PPHA) was successfully treated by endovascular occlusion with Guglielmi detachable coils. As both vertebral arteries were aplasitc, a microcatheter was advanced via PPHA. To the best of our knowledge, this is the first case report describing the treatment of a basilar top aneurysm through the PPHA.

GUIDELINES FOR THE SURGICAL TREATMENT OF UNRUPTURED INTRACRANIAL ANEURYSMS

THE MANAGEMENT OF unruptured cerebral aneurysms remains one of the most controversial topics in neurosurgery. To this end, we discuss the diagnosis and estimated prevalence of these lesions as well as review the literature regarding the rate of rupture for cerebral aneurysms and risks of operative intervention. Our interpretation of the literature concludes that aneurysms are present in approximately 1% of the adult population, varying between less than 1% in young adults to 4% in the elderly. The yearly risk of subarachnoid hemorrhage for an unruptured intracranial aneurysm is approximately 1% for lesions 7 to 10 mm in diameter. Based on these assumptions, we recommend that 1) with rare exceptions, all symptomatic unruptured aneurysms should be treated; 2) small, incidental aneurysms less than 5 mm in diameter should be managed conservatively in virtually all cases; 3) aneurysms larger than 5 mm in patients younger than 60 years of age should be seriously considered for treatment; 4) large, incidental aneurysms larger than 10 mm should be treated in nearly all patients younger than 70 years of age; and 5) microsurgical clipping rather than endovascular coiling should be the first treatment choice in low-risk cases. Critical to our guidelines is collaboration by a highly experienced cerebrovascular team of microneurosurgeons and endovascular neurosurgeons working at a tertiary medical center with a high case volume and using a decision-making paradigm designed to offer only low-risk treatments. In certain patients for whom both treatment and natural history carry high risks, such as those with giant aneurysms, nonoperative management is typically elected.

Relationship between aneurysm volume and histologic healing after coil embolization in elastase-induced aneurysms: a retrospective study

BACKGROUND AND PURPOSE

There are, to our knowledge, no histologic data correlating aneurysm volume with histologic healing following coil embolization of aneurysms. We report a retrospective study comparing histologic outcome with aneurysm volume in elastase-induced aneurysms in rabbits.

MATERIALS AND METHODS

Aneurysm volume and histologic healing after coil embolization were retrospectively analyzed in 37 elastase-induced aneurysms in rabbits. Aneurysm dimensions (including neck, width, height, and volume) were measured and calculated. Packing density (PD) was calculated. Angiographic results were evaluated as recurrence, stable, and progressive occlusion. An ordinal grading system was used to evaluate the histologic healing after embolization. Correlations among aneurysm volume, PD, and histologic healing were analyzed by conducting linear regression analysis.

RESULTS

For all the aneurysms in this study, mean aneurysm volume was 80.8 +/- 48.6 mm(3) (from 22 to 192 mm(3)), mean PD was 30.4 +/- 8.3% (from 17% to 49%), and mean histologic score was 6.1 +/- 2.0 (from 0.5 to 9.5), respectively. Correlations between aneurysm volume and PD, aneurysm volume and histologic healing, and aneurysm packing and histologic healing were all significant (P < .01).

CONCLUSION

In this study, aneurysms with smaller volumes and higher PD were associated with the most complete histologic healing. The incomplete healing seen in the larger aneurysms is consistent with the higher incidence of recurrences after endovascular treatment that is seen in large human aneurysms.

Aneurysms of the vertebrobasilar junction: incidence, clinical presentation, and outcome of endovascular treatment

BACKGROUND AND PURPOSE

The aim of this retrospective study was to report the incidence, clinical presentation, and midterm clinical and imaging results of endovascular treatment of 10 aneurysms of the vertebrobasilar junction.

MATERIALS AND METHODS

Between January 1995 and January 2007, 2112 aneurysms were treated in our institution. Ten aneurysms in 10 patients were located on the vertebrobasilar junction and 7 aneurysms (70%) were associated with proximal basilar fenestration. There were 5 men and 5 women, ranging from 29 to 75 years of age. Nine aneurysms presented with subarachnoid hemorrhage, and one was a giant partially thrombosed aneurysm with mass effect on the brain stem.

RESULTS

Nine ruptured aneurysms were treated by primary coil occlusion. One giant unruptured aneurysm was initially treated with bilateral vertebral artery occlusion, 2 months later followed by selective coil occlusion of the remaining aneurysm lumen via the posterior communicating artery. At imaging follow-up of 6-30 months in 7 patients, all aneurysms were adequately occluded. In 2 patients, the vertebrobasilar junction and distal vertebral arteries (including the aneurysm) thrombosed completely on follow-up without clinical sequelae.

CONCLUSION

Vertebrobasilar junction aneurysms are rare, with an incidence of 0.5% of treated aneurysms at our institution. Vertebrobasilar junction aneurysms are frequently associated with proximal basilar fenestration. Most patients present with subarachnoid hemorrhage. Endovascular treatment is effective and safe in excluding the aneurysms from the circulation.

Surgery of intracranial aneurysms previously treated endovascularly

OBJECTIVE

To perform a retrospective study on the patients who underwent aneurysmal surgery following endovascular treatment.

PATIENTS AND METHODS

We performed a retrospective study on eight patients who underwent aneurysmal surgery following endovascular treatment (-attempts) with gugliemi detachable coils (GDCs). The indications for surgery, surgical techniques and clinical outcomes were analyzed.

RESULTS

The indications for surgical treatment after GDC coiling of aneurysm were classified into three groups. First group: surgery of incompletely coiled aneurysms (n=4). Second group: surgery of mass effect on the neural structures due to coil compaction or rebleeding (n=2). Third group: surgery of vascular complications after endovascular procedure due to parent artery occlusion or thrombus propagation from aneurysm (n=2). Aneurysm obliterations could be performed in all cases confirmed by postoperative angiography. Six patients had an excellent outcome and returned to their profession. Patient's visual acuity was improved. One individual experienced right hemiparesis (grade IV/V) and hemihypesthesia.

CONCLUSIONS

Microsurgical clipping is rarely necessary for previously coiled aneurysms. Surgical treatment is uncommonly required when an acute complication arises during endovascular treatment, or when there is a dynamic change of a residual aneurysm configuration over time that is considered to be insecure.

Treatment of intracranial aneurysms with hydrogel coated expandable coils

BACKGROUND

Coiling of intracranial aneurysms with platinum coils sometimes results in relatively poor angiographic results which may be is related to low packing volumes achieved. Hydrogel coated expandable coils (HydroCoil) have been shown to achieve better aneurysm volume filling which may potentially result in lower recanalization rates. Currently there is limited clinical data on their safety and efficacy in aneurysm treatment.

METHODS

We analyzed data from a prospectively collected database on patients treated at the Toronto Western Hospital. The analysis included the patients' characteristics, aneurysm size, packing, procedure related complications, recanalization and clinical outcome.

RESULTS

Twenty-nine aneurysms were treated with HydroCoils only or in combination with other coils. The average calculated filling of the aneurysm volume was 74-76%. On the immediate post treatment angiograms, 44% of the berry type aneurysms were completely obliterated, 33% had a residual neck and, in 20%, a residual aneurysm was seen. Follow-up imaging was available in 23 cases. On imaging follow-up (from 2 days to 11 months) one dissecting aneurysm had recanalized. There were six technical/medical complications with no clinical consequences. Two clinically significant procedural related complications occurred.

CONCLUSIONS

HydroCoils can be used effectively to treat intracranial aneurysms. The volume expansion allows for much greater packing than described for bare platinum coils, which may result in better long-term results. The recanalization rate is low but the limited follow-up does not allow for any conclusion regarding the long-term outcome. The complication rate is similar to larger current series using bare platinum coils.